This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application V-TYPE APERTURE COUPLED CIRCULAR POLARIZATION PATCH ANTENNA USING MICROSTRIP LINE filed with the Korean Industrial Property Office on the 8th day of April 1999 and there duly assigned Ser. No. 12416/1999.
1. Field of the Invention
The present invention relates to satellite-based vehicle communication with a PCS base station and a satellite broadcasting receiver, and, more particularly, to a communication process and V-type aperture coupled circular polarization patch antenna using a microstrip line.
2. Description of the Related Art
Generally, a precise polarization adjustment is needed in a communication system in order to optimize the system and its operational functioning. There are various kinds of polarizations, including linear polarization, circular polarization and elliptical polarization. The design of polarization should be properly selected and used in conformity with the particular system in which the design is being applied. In a vehicle-mounted satellite communication system for example, it is preferable that polarization, which is independent of the moving direction of the vehicle, is used in order to maximize reception of electric waves from the satellite without fluctuation in the level of reception. Therefore, in satellite-based vehicle communication systems, the circular polarization is used in an effort to maintain a constant level of reception, regardless of the direction of movement of the vehicle.
Circular polarization can be produced only when two linear polarizations, which determine the direction of polarization, have the same amplitude and are orthogonal to each other so as to assure a relative phase difference of 90xc2x0. A microstrip patch antenna is adequate to satisfy these circular polarization generating conditions as well being suitable for mounting upon a vehicle. That is, the microstrip patch antenna is so thin as to create negligible air resistance and can be mass-produced by contemporary printing technology. Typically, the current distribution provided by the aperture formed in the circular patch of the antenna will be vectorially distributed at an interval of 90xc2x0, so that two frequencies radiated by linear differences in the lengths of the components of the aperture resonate. The impedances created by these differences in length, for example, the differences in length between protrusions from the circumference of the circular patch and an inner diameter of the patch, or alternatively, between protrusions and recesss, provide a phase difference of 90xc2x0 necessary to create a circular polarization generating conditions. I have found that there are some problems with conventional circular polarization patch antennas however, because the design of these antennas are complex and the manufacturing process is therefore unduly complicated.
It is therefore an object of the present invention to provide an improved process and aperture antenna.
It is another object to provide an aperture coupled circular polarization patch antenna using a microstrip line.
It is still another object to provide a simple design and easily executed process for manufacturing an aperture antenna.
It is yet another object to provide an aperture coupled circular polarization patch antenna using a microstrip line, in which the microstrip line and a patch are separated by a ground surface so that an active device is mounted on the feeding line to be capable of beam scanning of an array antenna.
It is still yet another object to provide a microstrip patch antenna that is adequate to satisfy these circular polarization generating conditions while being suitable for mounting upon a vehicle.
It is a further object to provide a microstrip patch antenna that is thin enough to create negligible air resistance and may be easily mass-produced by contemporary printing technology.
These and other objects may be achieved in the practice of the present invention, with a V type aperture coupled circular polarization patch antenna constructed with a microstrip line that is formed on a rear face of a dielectric substance, a ground surface that is formed on an entire face of the dielectric substance, a V type aperture that is formed at a desired angle on the basis of a portion of the ground surface, and which overlaps with the microstrip line, and a patch that is formed into a rectangular shape and is mounted at an upper portion of the aperture so as to cover the aperture. Preferably, the V type aperture is formed at an angle of 90xc2x0, with each length of the long and short sides of the patch being adjusted to provide a phase difference of 90xc2x0 according to mutual impedance, and size and length of the aperture being adjusted so as to have a phase difference of 90xc2x0 according to the mutual impedance.